The invention relates in general to an apparatus for examining tissue for abnormalities or anomalies through the use of endoscopic examinations. More specifically, the invention relates to an endoscopic apparatus that utilizes hyperspectral analysis to detect abnormality or anomaly conditions in tissue.
The characterization of the state of cells and tissues is one of the most demanding issues in medical and biological diagnostics. The problem in performing proper characterization has become increasingly important for the localization of tumorous tissue in the gastrointestinal (GI) tract, discrimination between adenomatous polyps from normal colonic tissue and hyperplastic polyps. The vast majority of colorectal carcinomas arise from adenomatous polyps, wherein the occurance of colorectal carcinomas ranks second only to lung cancer in the United States.
Different types of early detection methods have been suggested over the past decade. For example, an appraisal of pathological conditions of many lesions or abnormalities can be made be endoscopic observation alone, but there remains a margin for error that can be substantial for certain types of lesions. Furthermore, certain abnormalities of a microscopic nature, such as dysplasia, are usually unrecognizable by gross endoscopic observation. Microscopic assessment of biopsy specimens is necessary for many lesions discovered during endoscopy.
The fluorescence properties of fluorophores important in metabolism are characteristic of the states of cells and tissues. Conventional laser fluroscopes are valuable systems to measure sensitive autofluorescence signals of various samples. While this approach causes minimal disturbances to the specimen, conventional systems lack the required spatial resolution and therefore can be used only for local characterization.
Accordingly, there remains no adequate existing in vivo solution to appropriately identify and characterize abnormality conditions. It would therefore be desirable to provide an endoscopic apparatus that was capable of overcoming the difficulties associated with conventional approaches discussed above.
A hyperspectral imaging endoscopy apparatus is provided that utilizes spectral technology to acquire, process and exploit gastroscopic data. The apparatus allows for real time anomaly detection and identification. The apparatus includes an endoscope, a spectrometer and a processing unit that perform hyperspectral analysis on spectral data generated from the spectrometer. The endoscope and associated coupling optics are preferably optimized for cylindrical symmetry, thus allowing continuous inspection of gastrointestinal or arterial walls.
More specifically, the apparatus includes an endoscope including at least one imaging channel, a spectrometer coupled to the imaging camera, for example, an ICCD, CCD, CMOS or other type of imaging cameras, that generates spectral data in response to an optical signal received from the imaging channel, an optical coupling system that couples an output from the imaging channel to an input of the spectrometer, and a processing unit that performs hyperspectral analysis on the spectral data generated by the spectrometer to generate hyperspectral data. The processing unit correlates the hyperspectral data to spectral characteristics of abnormal tissue to thereby identify abnormal tissue or anomalies imaged by the endoscope through the imaging channel through the use of hyperspectral object detection algorithms.
In a preferred embodiment, a display is coupled to the processor, wherein the hyperspectral data is displayed on the display as a hyperspectral image. In addition, an imaging channel is optional provided that is coupled to an electronic imaging camera. The electronic imaging camera generates conventional image data that can also be viewed on the display as a standard image. If desired, the hyperspectral image and the standard image are simultaneously displayed to allow side-by-side comparison by a physician or operator.
The optical coupling system includes a prism and a mechanism that rotates the prism to rotate the output of the imaging channel with respect to the input of the spectrometer. When the prism is utilized, it is preferable to convert the hyperspectral data prior to display such that the hyperspectral image dimensionally corresponds with the standard image.
Alternatively, the optical coupling system includes a mirror and means for moving the mirror to translate the output of the imaging channel with respect to an input of the spectrometer.
Various features and advantages of the invention will become further apparent to those skilled in the art from the following detailed description of the preferred embodiments of the invention.